pfillion/mariadb repository overview

⁠MariaDB

These are docker images for MariaDB⁠ database. Mainly, it's to manage healthcheck⁠ with credential specified by secrets.

The base image is from official MariaDB⁠.

⁠Versions

• latest⁠ available as pfillion/mariadb:latest at Docker Hub⁠

⁠Volumes

• /var/lib/mysql
• /var/mariadb/backup

⁠Ports

• 3306

⁠Using a custom MySQL configuration file

The MariaDB startup configuration is specified in the file /etc/mysql/my.cnf, and that file in turn includes any files found in the /etc/mysql/conf.d directory that end with .cnf. Settings in files in this directory will augment and/or override settings in /etc/mysql/my.cnf. If you want to use a customized MySQL configuration, you can create your alternative configuration file in a directory on the host machine and then mount that directory location as /etc/mysql/conf.d inside the mariadb container.

If /my/custom/config-file.cnf is the path and name of your custom configuration file, you can start your mariadb container like this (note that only the directory path of the custom config file is used in this command):

docker run --name some-mariadb -v /my/custom:/etc/mysql/conf.d -e MARIADB_ROOT_PASSWORD=my-secret-pw -d mariadb:tag

This will start a new container some-mariadb where the MariaDB instance uses the combined startup settings from /etc/mysql/my.cnf and /etc/mysql/conf.d/config-file.cnf, with settings from the latter taking precedence.

⁠Environment Variables

When you start the mariadb image, you can adjust the configuration of the MariaDB instance by passing one or more environment variables on the docker run command line. Do note that none of the variables below will have any effect if you start the container with a data directory that already contains a database: any pre-existing database will always be left untouched on container startup.

⁠MARIADB_ROOT_PASSWORD

This variable is mandatory and specifies the password that will be set for the MariaDB root superuser account. In the above example, it was set to my-secret-pw.

⁠MARIADB_DATABASE

This variable is optional and allows you to specify the name of a database to be created on image startup. If a user/password was supplied (see below) then that user will be granted superuser access (corresponding to GRANT ALL⁠) to this database.

⁠MARIADB_USER, MARIADB_PASSWORD

These variables are optional, used in conjunction to create a new user and to set that user's password. This user will be granted superuser permissions (see above) for the database specified by the MARIADB_DATABASE variable. Both variables are required for a user to be created.

Do note that there is no need to use this mechanism to create the root superuser, that user gets created by default with the password specified by the MARIADB_ROOT_PASSWORD variable.

⁠MARIADB_ALLOW_EMPTY_PASSWORD

This is an optional variable. Set to yes to allow the container to be started with a blank password for the root user. NOTE: Setting this variable to yes is not recommended unless you really know what you are doing, since this will leave your MariaDB instance completely unprotected, allowing anyone to gain complete superuser access.

⁠MARIADB_RANDOM_ROOT_PASSWORD

This is an optional variable. Set to yes to generate a random initial password for the root user (using pwgen). The generated root password will be printed to stdout (GENERATED ROOT PASSWORD: .....).

⁠MOBYCRON_ENABLED

This is an optional variable. Set to true or 1 to enable mobycron deamon. The configuration is specified in the file /configs/config.json. By default, this configuration includes a daily backup of the server. The compressed backup file is created in the volume /var/mariadb/backup.

⁠Docker Secrets

As an alternative to passing sensitive information via environment variables, _FILE may be appended to the previously listed environment variables, causing the initialization script to load the values for those variables from files present in the container. In particular, this can be used to load passwords from Docker secrets stored in /run/secrets/<secret_name> files. For example:

docker run --name some-mysql -e MARIADB_ROOT_PASSWORD_FILE=/run/secrets/mysql-root -d mariadb:tag

Currently, this is only supported for MARIADB_ROOT_PASSWORD, MARIADB_ROOT_HOST, MARIADB_DATABASE, MARIADB_USER, and MARIADB_PASSWORD.

⁠Docker Healthcheck

This container provides a script that instructs Docker how to check if the mariadb server still working. For example:

healthcheck:
    test: ["CMD", "/usr/local/bin/healthcheck"]
    interval: 30s
    timeout: 30s
    retries: 5

⁠TODO

• Support FULL RESTORE on container startup
• A mode which allows testing backups via cron/docker job

⁠Authors

• pfillion⁠

⁠License

MIT